Question about conduit entering a pedestal type meter base

[jaggedben]

I don't know the history but it feels like this is an area the CMPs have deliberately not cleared up. It's always been confusing and never 100% clear to me. Wireways in particular seem like a very grey area. It sure seems to be a raceway (art 376) until I put any device in it, then it could be a box. Btw the meter section of a meter main strongly resembles a wireway.

Perhaps you're right and the NEC doesn't prohibit branch circuits and feeders running though meter sections. But it's pretty much a moot point, given utility rules probably everywhere. Bad practice and I would never do it. Plus I still think there's probably listing issues. Although I can't find any instructions that speak to it, good luck getting any manufacturer to approve branch circuits and feeders in the meter section of their meter/main. Also they keep adding more stuff to separate and insulate the service conductor parts in the disconnect sections, which makes little sense if you're allowed to completely defeat the purpose by running load side conductors through the meter section.

 

[electrofelon]

good luck getting any manufacturer to approve branch circuits and feeders in the meter section of their meter/main.

Again, where is it stated anywhere that I need manufacturer approval? Unless it's specifically prohibited in the instructions or installation manual I don't see an issue. (I do agree probably a moot point because of utility requirements).

 

[ggunn]

Again, where is it stated anywhere that I need manufacturer approval? Unless it's specifically prohibited in the instructions or installation manual I don't see an issue. (I do agree probably a moot point because of utility requirements).

I agree; the utility would be the sticking point. I have had a couple of them agree to letting us interconnect in their CT cans, but usually they do not want anything in their enclosures besides their own equipment and conductors.

 

[BroverCleveland]

I agree; the utility would be the sticking point. I have had a couple of them agree to letting us interconnect in their CT cans, but usually they do not want anything in their enclosures besides their own equipment and conductors.

I have experienced the same thing. Even on jobs where the utility owns the PV installation, they said no to interconnection in the CT cab.

 

[electrofelon]

I have experienced the same thing. Even on jobs where the utility owns the PV installation, they said no to interconnection in the CT cab.

Which makes no sense (presumably I'm preaching to the choir here). How is running a supply side connection conductor set into a CT cabinet any different than running multiple conductor sets under 230.40 exception #2, which is super common and surely not a problem. The two installations are mechanically indistinguishable.

 

[BroverCleveland]

Which makes no sense (presumably I'm preaching to the choir here). How is running a supply side connection conductor set into a CT cabinet any different than running multiple conductor sets under 230.40 exception #2, which is super common and surely not a problem. The two installations are mechanically indistinguishable.

Agreed. I also think the reason many AHJ's believe that a supply side connection is a parallel service is because the requirements for supply side connections are found with the services article. That being said, the definitions in both article 100 and 705 lead me to believe that service conductors belong to the utility, and therefore solar supply side conductors can't be service conductors.

 

[ggunn]

Which makes no sense (presumably I'm preaching to the choir here). How is running a supply side connection conductor set into a CT cabinet any different than running multiple conductor sets under 230.40 exception #2, which is super common and surely not a problem. The two installations are mechanically indistinguishable.

I agree, but most utilities I have dealt with consider the CT metering enclosure to be for their exclusive use, and they will not allow anyone else's equipment or conductors inside it. In one case the utility only relented and let us interconnect in their CT can when we showed them that there was no other way to make the interconnection without major reconstruction because all the existing equipment was built into the side of the customer's building. In the utility's CT can there was already a spare set of lugs on the load side of the CT's that were the perfect size for our conductors, so it worked out, but that was an exception.

 

[electrofelon]

.....and they will not allow anyone else's equipment or conductors inside it.

But the "normal" conductors are allowed? What if in these cases instead of calling it a supply side connection you said " we are adding another set of service conductors per 230.40 exception #2"?

 

[ggunn]

But the "normal" conductors are allowed? What if in these cases instead of calling it a supply side connection you said " we are adding another set of service conductors per 230.40 exception #2"?

A lot of utilities lock up the enclosures and won't even let us open them to look at what is inside, so I would hazard a guess that the answer would be no.

 

[electrofelon]

A lot of utilities lock up the enclosures and won't even let us open them to look at what is inside, so I would hazard a guess that the answer would be no.

So no changes or upgrades are allowed after initial construction even if within equipment capacity and there are sufficient terminals? Doesn't make any sense. I don't see why they would have an issue if you said " we are adding another service disconnect" or "we are adding another parallel set"

 

[kwired]

Agreed. I also think the reason many AHJ's believe that a supply side connection is a parallel service is because the requirements for supply side connections are found with the services article. That being said, the definitions in both article 100 and 705 lead me to believe that service conductors belong to the utility, and therefore solar supply side conductors can't be service conductors.

Art 100 definition does not say that.



Location of the service point is the key here. Meters can be and often are on customer side of service point, yet locked by POCO, and POCO still can dictate how they are installed. If you don't comply they won't energize you.

Typical overhead drop type service often the service point is at the connection of the drop conductors to the riser conductors. Those conductors are still service conductors until they hit the service disconnecting means whether there is a meter in line with them or not.

 

[ggunn]

So no changes or upgrades are allowed after initial construction even if within equipment capacity and there are sufficient terminals? Doesn't make any sense. I don't see why they would have an issue if you said " we are adding another service disconnect" or "we are adding another parallel set"

You know I am talking about the utility revenue meter CT enclosure, right? For many of these utility CT cans the only things in the enclosure are the CTs and maybe some terminals. Any changes inside them have to be done with the participation of the utility.

 

[electrofelon]

You know I am talking about the utility revenue meter CT enclosure, right? For many of these utility CT cans the only things in the enclosure are the CTs and maybe some terminals. Any changes inside them have to be done with the participation of the utility.

Right. And the customers conductors pass thru it (usually, of course subject to where the service point is. Of course you need utility approval to get in there and change stuff, but what I am struggling to understand is why there would be an issue adding more conductors in there if it would have been fine when it was a originally first built??

 

[ggunn]

Right. And the customers conductors pass thru it (usually, of course subject to where the service point is. Of course you need utility approval to get in there and change stuff, but what I am struggling to understand is why there would be an issue adding more conductors in there if it would have been fine when it was a originally first built??

Struggle all you want but that's the way it is; your argument isn't with me.

 

[Carultch]

Right. And the customers conductors pass thru it (usually, of course subject to where the service point is. Of course you need utility approval to get in there and change stuff, but what I am struggling to understand is why there would be an issue adding more conductors in there if it would have been fine when it was a originally first built??

If it were customer-owned metering equipment, you could do whatever you want in it that complies with the NEC, just as you could do within a switch or panelboard in general.

The problem comes, when it is a utility service meter base, specifically. The utilities generally don't want to see any foreign connectors in their sockets, other than what the manufacturer provides as a standard lug. You could tap onto the otherwise-vacant second terminal in a 320A meterbase, and it would be no different than adding a second service disconnect. But installing a foreign connector like a Polaris block or an insulation piericing connector, is something you should avoid without written approval from the utility. There are very few utilities who are willing to work with you, for an "out of the box" solution involving a meter socket that hosts their meter.

 

[kwired]

If it were customer-owned metering equipment, you could do whatever you want in it that complies with the NEC, just as you could do within a switch or panelboard in general.

The problem comes, when it is a utility service meter base, specifically. The utilities generally don't want to see any foreign connectors in their sockets, other than what the manufacturer provides as a standard lug. You could tap onto the otherwise-vacant second terminal in a 320A meterbase, and it would be no different than adding a second service disconnect. But installing a foreign connector like a Polaris block or an insulation piericing connector, is something you should avoid without written approval from the utility. There are very few utilities who are willing to work with you, for an "out of the box" solution involving a meter socket that hosts their meter.

Some 320 and other higher capacity meter bases simply come with studs and you mount your own lugs to match what you need for your conductors.

CT cabinets I run into are just an empty cabinet, POCO bolts CT's to back wall, often uses Polaris or other similar insulated multiport connectors to connect conductors. Or they sometimes have a bare multiport bar they use and have an insulating cover that fits over it. Hardly ever see an insulated panel mount terminal block of any kind.

 

[electrofelon]

If it were customer-owned metering equipment, you could do whatever you want in it that complies with the NEC, just as you could do within a switch or panelboard in general.

The problem comes, when it is a utility service meter base, specifically. The utilities generally don't want to see any foreign connectors in their sockets, other than what the manufacturer provides as a standard lug. You could tap onto the otherwise-vacant second terminal in a 320A meterbase, and it would be no different than adding a second service disconnect. But installing a foreign connector like a Polaris block or an insulation piericing connector, is something you should avoid without written approval from the utility. There are very few utilities who are willing to work with you, for an "out of the box" solution involving a meter socket that hosts their meter.

I am not even talking about making any splices or taps in a meter socket or CT cabinet. I am talking about running another set of conductors to it where there are spare ports and/or appropriate listed lugs to make the connection.

 

[electrofelon]

Some 320 and other higher capacity meter bases simply come with studs and you mount your own lugs to match what you need for your conductors.

Around here the class 320 sockets we get do not come with lugs, just 3/8 studs. I have bolted on whatever mechanical lugs suit me, but usually use stacked crimp lugs. I DECIDE!

 

[ggunn]

I am not even talking about making any splices or taps in a meter socket or CT cabinet. I am talking about running another set of conductors to it where there are spare ports and/or appropriate listed lugs to make the connection.

I get it. In a case I referenced earlier in this thread the utility revenue monitoring CT can had two sets of service conductors running through it with three port lugs on each side of the CTs., so there was a spare set of lugs on the load side that were an electrically perfect site for a supply side PV interconnection (the CT can was unlocked so we opened it and looked). When we asked the utility if we could land our PV conductors in those spare lugs, they initially told us that we couldn't, but when we showed them that we could not land them anywhere else without it requiring major reconstruction of the existing equipment wall, they relented. It required that the customer request a variance to their policy but they granted it.

My point isn't that they let us connect in their CT can but that they wouldn't unless there was no other way to interconnect the PV system without it requiring the customer (who is of course theirs as well as ours) to pay for an expensive electrical and structural renovation of that part of their building and to be without power while it was being done.

 

[electrofelon]

. It required that the customer request a variance to their policy but they granted it.
.

What exactly is the policy? I guess they could state something like "supply side PV interconnections shall not be made in the CT enclosure". But then seems like you could just call it 230.40 exception #2, add another set to a MB combiner panel, and connect load side to that using the sum of all OCPD excluding the OCPD protecting the busbar rule.